Comparison of time-resolved fluoroimmunoassay for determining hexoestrol residues in chicken muscle tissues based on polyclonal antibodies with liquid chromatography and tandem mass spectrometry.

A time-resolved fluoroimmunoassay (TR-FIA) was developed for the determination of hexoestrol (HES) residues in animal tissues. The limit of detection (LOD) was determined to be 0.02 ng g(-1) and the limit of quantification (LOQ) was less than 0.12 ng g(-1). The results obtained by the TR-FIA and ELISA showed a good correlation. The established TR-FIA was validated for the determination of market chicken muscle tissues and confirmed by high-performance liquid chromatography and tandem mass spectrometry (LC-MS-MS). This proposed technique could be applied to routine residue analysis.